curl: fix --upload-file . hangs if delay in STDIN

Attempt to unpause a busy read in the CURLOPT_XFERINFOFUNCTION.

When uploading from stdin in non-blocking mode, a delay in reading
the stream (EAGAIN) causes curl to pause sending data
(CURL_READFUNC_PAUSE).  Prior to this change, a busy read was
detected and unpaused only in the CURLOPT_WRITEFUNCTION handler.
This change performs the same busy read handling in a
CURLOPT_XFERINFOFUNCTION handler.

Fixes #2051
Closes #4599
Reported-by: bdry on github

src/tool_cb_prg.c

@@ -32,6 +32,7 @@
 #include "tool_cfgable.h"
 #include "tool_cb_prg.h"
 #include "tool_util.h"
+#include "tool_operate.h"
 
 #include "memdebug.h" /* keep this as LAST include */
 
@@ -121,7 +122,10 @@ int tool_progress_cb(void *clientp,
      and this new edition inherits some of his concepts. */
 
   struct timeval now = tvnow();
-  struct ProgressData *bar = (struct ProgressData *)clientp;
+  struct per_transfer *per = clientp;
+  struct OutStruct *outs = &per->outs;
+  struct OperationConfig *config = outs->config;
+  struct ProgressData *bar = &per->progressbar;
   curl_off_t total;
   curl_off_t point;
 
@@ -191,6 +195,11 @@ int tool_progress_cb(void *clientp,
   bar->prev = point;
   bar->prevtime = now;
 
+  if(config->readbusy) {
+    config->readbusy = FALSE;
+    curl_easy_pause(per->curl, CURLPAUSE_CONT);
+  }
+
   return 0;
 }
 

src/tool_cb_rea.c

@@ -27,6 +27,7 @@
 
 #include "tool_cfgable.h"
 #include "tool_cb_rea.h"
+#include "tool_operate.h"
 
 #include "memdebug.h" /* keep this as LAST include */
 
@@ -52,3 +53,28 @@ size_t tool_read_cb(void *buffer, size_t sz, size_t nmemb, void *userdata)
   in->config->readbusy = FALSE;
   return (size_t)rc;
 }
+
+/*
+** callback for CURLOPT_XFERINFOFUNCTION used to unpause busy reads
+*/
+
+int tool_readbusy_cb(void *clientp,
+                     curl_off_t dltotal, curl_off_t dlnow,
+                     curl_off_t ultotal, curl_off_t ulnow)
+{
+  struct per_transfer *per = clientp;
+  struct OutStruct *outs = &per->outs;
+  struct OperationConfig *config = outs->config;
+
+  (void)dltotal;  /* unused */
+  (void)dlnow;  /* unused */
+  (void)ultotal;  /* unused */
+  (void)ulnow;  /* unused */
+
+  if(config->readbusy) {
+    config->readbusy = FALSE;
+    curl_easy_pause(per->curl, CURLPAUSE_CONT);
+  }
+
+  return per->noprogress? 0 : CURL_PROGRESSFUNC_CONTINUE;
+}

src/tool_cb_rea.h

@@ -29,4 +29,12 @@
 
 size_t tool_read_cb(void *buffer, size_t sz, size_t nmemb, void *userdata);
 
+/*
+** callback for CURLOPT_XFERINFOFUNCTION used to unpause busy reads
+*/
+
+int tool_readbusy_cb(void *clientp,
+                     curl_off_t dltotal, curl_off_t dlnow,
+                     curl_off_t ultotal, curl_off_t ulnow);
+
 #endif /* HEADER_CURL_TOOL_CB_REA_H */

src/tool_operate.c

@@ -1080,11 +1080,11 @@ static CURLcode single_transfer(struct GlobalConfig *global,
            isatty(fileno(outs->stream)))
           /* we send the output to a tty, therefore we switch off the progress
              meter */
-          global->noprogress = global->isatty = TRUE;
+          per->noprogress = global->noprogress = global->isatty = TRUE;
         else {
           /* progress meter is per download, so restore config
              values */
-          global->noprogress = orig_noprogress;
+          per->noprogress = global->noprogress = orig_noprogress;
           global->isatty = orig_isatty;
         }
 
@@ -1573,7 +1573,14 @@ static CURLcode single_transfer(struct GlobalConfig *global,
           /* we want the alternative style, then we have to implement it
              ourselves! */
           my_setopt(curl, CURLOPT_XFERINFOFUNCTION, tool_progress_cb);
-          my_setopt(curl, CURLOPT_XFERINFODATA, &per->progressbar);
+          my_setopt(curl, CURLOPT_XFERINFODATA, per);
+        }
+        else if(per->uploadfile && !strcmp(per->uploadfile, ".")) {
+          /* when reading from stdin in non-blocking mode, we use the progress
+             function to unpause a busy read */
+          my_setopt(curl, CURLOPT_NOPROGRESS, 0L);
+          my_setopt(curl, CURLOPT_XFERINFOFUNCTION, tool_readbusy_cb);
+          my_setopt(curl, CURLOPT_XFERINFODATA, per);
         }
 
         /* new in libcurl 7.24.0: */

src/tool_operate.h

@@ -44,6 +44,7 @@ struct per_transfer {
   char *outfile;
   bool infdopen; /* TRUE if infd needs closing */
   int infd;
+  bool noprogress;
   struct ProgressData progressbar;
   struct OutStruct outs;
   struct OutStruct heads;

src/tool_progress.c

@@ -95,10 +95,18 @@ int xferinfo_cb(void *clientp,
                 curl_off_t ulnow)
 {
   struct per_transfer *per = clientp;
+  struct OutStruct *outs = &per->outs;
+  struct OperationConfig *config = outs->config;
   per->dltotal = dltotal;
   per->dlnow = dlnow;
   per->ultotal = ultotal;
   per->ulnow = ulnow;
+
+  if(config->readbusy) {
+    config->readbusy = FALSE;
+    curl_easy_pause(per->curl, CURLPAUSE_CONT);
+  }
+
   return 0;
 }